Vitamin D plays a vital role in maintaining bone health by aiding calcium absorption and supporting immune function. Many individuals do not receive sufficient vitamin D from sunlight or diet, making supplements necessary. The duration of vitamin D supplementation varies based on individual factors such as initial vitamin levels, lifestyle, and geographic location. For those addressing a deficiency, higher doses are typically recommended for a few months to restore healthy levels, followed by a maintenance dose of 15 to 20 mcg (600 to 800 IU) per day for most adults. However, excessive intake can lead to hypercalcemia, causing serious complications like kidney damage. Regular blood tests are advised to monitor vitamin D levels and adjust supplementation as needed. It is essential to consult a healthcare professional before making any changes to supplementation regimens.